From e0b751bee3250066959dc2cf2dbae3d0aed0d953 Mon Sep 17 00:00:00 2001
From: Miciah Masters <miciah.masters@gmail.com>
Date: Fri, 1 Jun 2018 02:59:57 -0400
Subject: [PATCH] Avoid non-idempotent use of push in init code

Replace push with add-to-list in layer init functions and related code.

Modify spacemacs|add-toggle to check for and update an existing toggle in
spacemacs-toggles and only create a new toggle if none already existed.

Replace a conditional push onto erc-packages with use of :toggle.

When initializing which-key, set which-key-replacement-alist to its default
or customized setting before adding all the Spacemacs replacements.  We
want to keep the stock replacements but avoid adding duplicates of the
Spacemacs replacements.

Replace the emacs-lisp-mode-hook lambda with a named function to avoid
adding duplicate hooks (which can add duplicate definitions of the
evil-surround pair).
---
 core/core-configuration-layer.el              |  2 +-
 core/core-toggle.el                           | 10 ++--
 doc/LAYERS.org                                |  4 +-
 layers/+chat/erc/packages.el                  | 46 +++++++++----------
 .../spacemacs-bootstrap/packages.el           |  7 ++-
 layers/+email/mu4e/config.el                  |  2 +-
 layers/+frameworks/react/packages.el          |  2 +-
 layers/+lang/clojure/packages.el              |  2 +-
 layers/+lang/d/packages.el                    |  2 +-
 layers/+lang/emacs-lisp/funcs.el              |  8 ++++
 layers/+lang/emacs-lisp/packages.el           |  4 +-
 layers/+lang/go/packages.el                   |  2 +-
 layers/+lang/haskell/funcs.el                 |  4 +-
 layers/+lang/java/README.org                  |  4 +-
 layers/+lang/java/packages.el                 |  2 +-
 layers/+lang/nim/packages.el                  |  2 +-
 layers/+lang/php/packages.el                  |  2 +-
 layers/+lang/ruby/packages.el                 |  2 +-
 layers/+lang/rust/packages.el                 |  2 +-
 layers/+lang/scala/README.org                 |  4 +-
 .../+spacemacs/spacemacs-visual/packages.el   |  4 +-
 layers/+tools/dash/packages.el                |  2 +-
 layers/+tools/shell/packages.el               |  4 +-
 23 files changed, 66 insertions(+), 57 deletions(-)

diff --git a/core/core-configuration-layer.el b/core/core-configuration-layer.el
index 55e893eee..2bfdb0323 100644
--- a/core/core-configuration-layer.el
+++ b/core/core-configuration-layer.el
@@ -1428,7 +1428,7 @@ discovery."
                                  sub)))
                   (spacemacs-buffer/message "-> Discovered category: %S"
                                             category)
-                  (push category configuration-layer-categories)
+                  (add-to-list 'configuration-layer-categories category)
                   (setq search-paths (cons sub search-paths))))
                ((eq 'layer type)
                 (let* ((layer-name-str (file-name-nondirectory sub))
diff --git a/core/core-toggle.el b/core/core-toggle.el
index f69bbb3e1..8a970dca5 100644
--- a/core/core-toggle.el
+++ b/core/core-toggle.el
@@ -95,10 +95,12 @@ used."
                                    ,condition)
                            t)))
     `(progn
-       (push (append '(,name)
-                     '(:function ,wrapper-func :predicate ,wrapper-func-status)
-                     ',props)
-             spacemacs-toggles)
+       (let ((properties (append '(:function ,wrapper-func :predicate ,wrapper-func-status)
+                                 ',props))
+             (cell (assq ',name spacemacs-toggles)))
+         (if cell
+             (setcdr cell properties)
+           (push (cons ',name properties) spacemacs-toggles)))
        ;; toggle function
        (defun ,wrapper-func ,(if prefix-arg-var (list prefix-arg-var) ())
          ,(format "Toggle %s on and off." (symbol-name name))
diff --git a/doc/LAYERS.org b/doc/LAYERS.org
index 8e5199790..69528fb7b 100644
--- a/doc/LAYERS.org
+++ b/doc/LAYERS.org
@@ -119,10 +119,10 @@ loaded before their code runs.
 When loaded using =require=, Emacs looks for files in its /load path/. This is
 nothing more than a list of paths where elisp files can be found, and you can
 inspect it through ~SPC h d v load-path~ in Spacemacs. To add to the load path,
-simply push to this list, e.g.
+simply add to this list, e.g.
 
 #+begin_src emacs-lisp
-(push "/some/path/" load-path)
+(add-to-list 'load-path "/some/path/")
 #+end_src
 
 ** Auto-loading
diff --git a/layers/+chat/erc/packages.el b/layers/+chat/erc/packages.el
index 39fa11a39..637ff8299 100644
--- a/layers/+chat/erc/packages.el
+++ b/layers/+chat/erc/packages.el
@@ -9,30 +9,28 @@
 ;;
 ;;; License: GPLv3
 
-(setq erc-packages
-      '(
-        company
-        company-emoji
-        emoji-cheat-sheet-plus
-        erc
-        (erc-gitter :location (recipe
-                               :fetcher github
-                               :repo "jleechpe/erc-gitter")
-                    :excluded t)
-        erc-hl-nicks
-        erc-image
-        (erc-sasl :location local)
-        erc-social-graph
-        (erc-tex :location local)
-        erc-view-log
-        (erc-yank :location local :excluded t)
-        erc-yt
-        linum
-        persp-mode
-        ))
-
-(when (spacemacs/system-is-mac)
-  (push 'erc-terminal-notifier erc-packages))
+(defconst erc-packages
+  '(
+    company
+    company-emoji
+    emoji-cheat-sheet-plus
+    erc
+    (erc-gitter :location (recipe
+                           :fetcher github
+                           :repo "jleechpe/erc-gitter")
+                :excluded t)
+    erc-hl-nicks
+    erc-image
+    (erc-sasl :location local)
+    erc-social-graph
+    (erc-terminal-notifier :toggle (spacemacs/system-is-mac))
+    (erc-tex :location local)
+    erc-view-log
+    (erc-yank :location local :excluded t)
+    erc-yt
+    linum
+    persp-mode
+    ))
 
 (defun erc/post-init-company ()
   (spacemacs|add-company-backends :backends company-capf :modes erc-mode))
diff --git a/layers/+distributions/spacemacs-bootstrap/packages.el b/layers/+distributions/spacemacs-bootstrap/packages.el
index 350c0b06d..6100b8cb7 100644
--- a/layers/+distributions/spacemacs-bootstrap/packages.el
+++ b/layers/+distributions/spacemacs-bootstrap/packages.el
@@ -67,7 +67,7 @@
   (evil-mode 1)
 
   ;; Use evil as a default jump handler
-  (push 'evil-goto-definition spacemacs-default-jump-handlers)
+  (add-to-list 'spacemacs-default-jump-handlers 'evil-goto-definition)
 
   (require 'cl)
   ;; State cursors
@@ -255,7 +255,7 @@
   (define-key evil-inner-text-objects-map "g" 'evil-inner-buffer)
 
   ;; turn off evil in corelv buffers
-  (push '("\\*LV\\*") evil-buffer-regexps)
+  (add-to-list 'evil-buffer-regexps '("\\*LV\\*"))
 
   ;; replace `dired-goto-file' with `helm-find-files', since `helm-find-files'
   ;; can do the same thing and with fuzzy matching and other features.
@@ -315,6 +315,9 @@
 
   ;; Needed to avoid nil variable error before update to recent which-key
   (defvar which-key-replacement-alist nil)
+  ;; Reset to the default or customized value before adding our values in order
+  ;; to make this initialization code idempotent.
+  (custom-reevaluate-setting 'which-key-replacement-alist)
   ;; Replace rules for better naming of functions
   (let ((new-descriptions
          ;; being higher in this list means the replacement is applied later
diff --git a/layers/+email/mu4e/config.el b/layers/+email/mu4e/config.el
index f6b1a0794..5f44a62d2 100644
--- a/layers/+email/mu4e/config.el
+++ b/layers/+email/mu4e/config.el
@@ -35,4 +35,4 @@
   "Modes that are associated with mu4e buffers.")
 
 (when mu4e-installation-path
-  (push mu4e-installation-path load-path))
+  (add-to-list 'load-path mu4e-installation-path))
diff --git a/layers/+frameworks/react/packages.el b/layers/+frameworks/react/packages.el
index 01b7d2e65..c310d6fe0 100644
--- a/layers/+frameworks/react/packages.el
+++ b/layers/+frameworks/react/packages.el
@@ -63,7 +63,7 @@
            (progn (goto-char (match-beginning 1))
                   (not (spacemacs//react-inside-string-or-comment-q)))))
 
-    (push (cons #'+javascript-jsx-file-p 'rjsx-mode) magic-mode-alist)
+    (add-to-list 'magic-mode-alist (cons #'+javascript-jsx-file-p 'rjsx-mode))
 
     ;; setup rjsx backend
     (add-hook 'rjsx-mode-local-vars-hook #'spacemacs//react-setup-backend)
diff --git a/layers/+lang/clojure/packages.el b/layers/+lang/clojure/packages.el
index d6e008573..bc2305329 100644
--- a/layers/+lang/clojure/packages.el
+++ b/layers/+lang/clojure/packages.el
@@ -178,7 +178,7 @@
     (progn
       ;; add support for golden-ratio
       (with-eval-after-load 'golden-ratio
-        (push 'cider-popup-buffer-quit-function golden-ratio-extra-commands))
+        (add-to-list 'golden-ratio-extra-commands 'cider-popup-buffer-quit-function))
       ;; add support for evil
       (evil-set-initial-state 'cider-stacktrace-mode 'motion)
       (evil-set-initial-state 'cider-popup-buffer-mode 'motion)
diff --git a/layers/+lang/d/packages.el b/layers/+lang/d/packages.el
index 8d356dec2..d4c195074 100644
--- a/layers/+lang/d/packages.el
+++ b/layers/+lang/d/packages.el
@@ -26,7 +26,7 @@
 (defun d/post-init-company ()
   ;; Need to convince company that this C-derived mode is a code mode.
   (with-eval-after-load 'company-dabbrev-code
-    (push 'd-mode company-dabbrev-code-modes)))
+    (add-to-list 'company-dabbrev-code-modes 'd-mode)))
 
 (defun d/init-company-dcd ()
   (use-package company-dcd
diff --git a/layers/+lang/emacs-lisp/funcs.el b/layers/+lang/emacs-lisp/funcs.el
index 33f35f379..54a1566af 100644
--- a/layers/+lang/emacs-lisp/funcs.el
+++ b/layers/+lang/emacs-lisp/funcs.el
@@ -105,3 +105,11 @@ Requires smartparens because all movement is done using `sp-forward-symbol'."
     (save-excursion
       (sp-forward-symbol)
       (call-interactively 'eval-last-sexp))))
+
+
+;; elisp comment text-object definition
+
+(defun spacemacs//define-elisp-comment-text-object ()
+  "Define a text object and a surround pair for elisp comments.
+Intended for use in mode hooks."
+  (spacemacs|define-text-object ";" "elisp-comment" ";; " ""))
diff --git a/layers/+lang/emacs-lisp/packages.el b/layers/+lang/emacs-lisp/packages.el
index df1126adc..45d2d2e29 100644
--- a/layers/+lang/emacs-lisp/packages.el
+++ b/layers/+lang/emacs-lisp/packages.el
@@ -231,9 +231,7 @@
             "th" 'overseer-help)))
 
 (defun emacs-lisp/post-init-evil ()
-  (add-hook 'emacs-lisp-mode-hook
-            (lambda ()
-              (spacemacs|define-text-object ";" "elisp-comment" ";; " ""))))
+  (add-hook 'emacs-lisp-mode-hook #'spacemacs//define-elisp-comment-text-object))
 
 (defun emacs-lisp/pre-init-evil-cleverparens ()
   (spacemacs|use-package-add-hook evil-cleverparens
diff --git a/layers/+lang/go/packages.el b/layers/+lang/go/packages.el
index 534b1d073..cf6a06aba 100644
--- a/layers/+lang/go/packages.el
+++ b/layers/+lang/go/packages.el
@@ -51,7 +51,7 @@
     :pre-config
     (dolist (var '("GOPATH" "GOROOT" "GO15VENDOREXPERIMENT") exec-path-from-shell-variables)
       (unless (or (member var exec-path-from-shell-variables) (getenv var))
-        (push var exec-path-from-shell-variables)))))
+        (add-to-list 'exec-path-from-shell-variables var)))))
 
 (defun go/init-go-mode()
   (use-package go-mode
diff --git a/layers/+lang/haskell/funcs.el b/layers/+lang/haskell/funcs.el
index d2fb09318..5c869a56d 100644
--- a/layers/+lang/haskell/funcs.el
+++ b/layers/+lang/haskell/funcs.el
@@ -52,7 +52,7 @@
   (spacemacs|add-company-backends
     :backends (dante-company company-dabbrev-code company-yasnippet)
     :modes haskell-mode)
-  (push 'xref-find-definitions spacemacs-jump-handlers)
+  (add-to-list 'spacemacs-jump-handlers 'xref-find-definitions)
   (dante-mode)
   (dolist (mode haskell-modes)
     (spacemacs/set-leader-keys-for-major-mode mode
@@ -68,7 +68,7 @@
   (spacemacs|add-company-backends
     :backends (company-intero company-dabbrev-code company-yasnippet)
     :modes haskell-mode)
-  (push 'intero-goto-definition spacemacs-jump-handlers)
+  (add-to-list 'spacemacs-jump-handlers 'intero-goto-definition)
   (intero-mode)
   (dolist (mode haskell-modes)
     (spacemacs/set-leader-keys-for-major-mode mode
diff --git a/layers/+lang/java/README.org b/layers/+lang/java/README.org
index 8ec07cbf7..1a170f5c5 100644
--- a/layers/+lang/java/README.org
+++ b/layers/+lang/java/README.org
@@ -104,8 +104,8 @@ If you want to use the Ensime backend, you should modify your =~/.spacemacs= to
 use the recommended Ensime version (Stable). Please add the following lines to
 =dotspacemacs/user-init=:
 #+BEGIN_SRC emacs-lisp
-  (push '("melpa-stable" . "stable.melpa.org/packages/") configuration-layer-elpa-archives)
-  (push '(ensime . "melpa-stable") package-pinned-packages)
+  (add-to-list 'configuration-layer-elpa-archives '("melpa-stable" . "stable.melpa.org/packages/"))
+  (add-to-list 'package-pinned-packages '(ensime . "melpa-stable"))
 #+END_SRC
 
 * Backends
diff --git a/layers/+lang/java/packages.el b/layers/+lang/java/packages.el
index 37d4be15f..82a19b64d 100644
--- a/layers/+lang/java/packages.el
+++ b/layers/+lang/java/packages.el
@@ -297,7 +297,7 @@
 ;;       (progn
 ;;         (spacemacs//ensime-init 'java-mode t nil)
 ;;         (when (configuration-layer/package-used-p 'company)
-;;           (push 'ensime-company company-backends-java-mode)))
+;;           (add-to-list 'company-backends-java-mode 'ensime-company)))
 ;;       :config
 ;;       (progn
 ;;         (spacemacs/ensime-configure-keybindings 'java-mode)))))
diff --git a/layers/+lang/nim/packages.el b/layers/+lang/nim/packages.el
index e834a7f9e..02878565f 100644
--- a/layers/+lang/nim/packages.el
+++ b/layers/+lang/nim/packages.el
@@ -22,7 +22,7 @@
     :init
     (progn
       (add-hook 'nim-mode-hook 'nimsuggest-mode)
-      (push 'nimsuggest-find-definition spacemacs-jump-handlers-nim-mode))
+      (add-to-list 'spacemacs-jump-handlers-nim-mode 'nimsuggest-find-definition))
     :config
     (progn
       (defun spacemacs/nim-compile-run ()
diff --git a/layers/+lang/php/packages.el b/layers/+lang/php/packages.el
index a3ace4f63..06fbf50e1 100644
--- a/layers/+lang/php/packages.el
+++ b/layers/+lang/php/packages.el
@@ -70,7 +70,7 @@
     :defer t
     :init
     (progn
-      (push 'ac-php-find-symbol-at-point spacemacs-jump-handlers-php-mode)
+      (add-to-list 'spacemacs-jump-handlers-php-mode 'ac-php-find-symbol-at-point)
       (add-hook 'php-mode-hook 'ac-php-core-eldoc-setup)
       (spacemacs|add-company-backends
         :modes php-mode
diff --git a/layers/+lang/ruby/packages.el b/layers/+lang/ruby/packages.el
index 4efa98a9a..0d0cc81bd 100644
--- a/layers/+lang/ruby/packages.el
+++ b/layers/+lang/ruby/packages.el
@@ -57,7 +57,7 @@
       :modes ruby-mode enh-ruby-mode))
   (with-eval-after-load 'company-dabbrev-code
     (dolist (mode '(ruby-mode enh-ruby-mode))
-      (push mode company-dabbrev-code-modes))))
+      (add-to-list 'company-dabbrev-code-modes mode))))
 
 (defun ruby/init-chruby ()
   (use-package chruby
diff --git a/layers/+lang/rust/packages.el b/layers/+lang/rust/packages.el
index 9438c5061..8610b7619 100644
--- a/layers/+lang/rust/packages.el
+++ b/layers/+lang/rust/packages.el
@@ -96,7 +96,7 @@
     :pre-config
     (let ((var "RUST_SRC_PATH"))
       (unless (or (member var exec-path-from-shell-variables) (getenv var))
-        (push var exec-path-from-shell-variables)))))
+        (add-to-list 'exec-path-from-shell-variables var)))))
 
 (defun rust/init-racer ()
   (use-package racer
diff --git a/layers/+lang/scala/README.org b/layers/+lang/scala/README.org
index 19de0549b..fad1f7295 100644
--- a/layers/+lang/scala/README.org
+++ b/layers/+lang/scala/README.org
@@ -39,8 +39,8 @@ file.
 Then, you should modify your =~/.spacemacs= to use the recommended Ensime
 version (Stable). Please add the following lines to =dotspacemacs/user-init=:
 #+BEGIN_SRC emacs-lisp
-  (push '("melpa-stable" . "stable.melpa.org/packages/") configuration-layer-elpa-archives)
-  (push '(ensime . "melpa-stable") package-pinned-packages)
+  (add-to-list 'configuration-layer-elpa-archives '("melpa-stable" . "stable.melpa.org/packages/"))
+  (add-to-list 'package-pinned-packages '(ensime . "melpa-stable"))
 #+END_SRC
 
 * Ensime
diff --git a/layers/+spacemacs/spacemacs-visual/packages.el b/layers/+spacemacs/spacemacs-visual/packages.el
index 399818d7d..06cd09447 100644
--- a/layers/+spacemacs/spacemacs-visual/packages.el
+++ b/layers/+spacemacs/spacemacs-visual/packages.el
@@ -30,7 +30,7 @@
     :init
     (setq desktop-dirname spacemacs-cache-directory)
     :config
-    (push spacemacs-cache-directory desktop-path)))
+    (add-to-list 'desktop-path spacemacs-cache-directory)))
 
 (defun spacemacs-visual/init-fill-column-indicator ()
   (use-package fill-column-indicator
@@ -40,7 +40,7 @@
       (setq fci-rule-width 1)
       ;; manually register the minor mode since it does not define any
       ;; lighter
-      (push '(fci-mode "") minor-mode-alist)
+      (add-to-list 'minor-mode-alist '(fci-mode ""))
       (spacemacs|add-toggle fill-column-indicator
         :status fci-mode
         :on (turn-on-fci-mode)
diff --git a/layers/+tools/dash/packages.el b/layers/+tools/dash/packages.el
index 64433adeb..09b5a0503 100644
--- a/layers/+tools/dash/packages.el
+++ b/layers/+tools/dash/packages.el
@@ -38,4 +38,4 @@
             "dD" 'zeal-at-point-set-docset)
     :config
     ;; This lets users seach in multiple docsets
-    (push '(web-mode . "html,css,javascript") zeal-at-point-mode-alist)))
+    (add-to-list 'zeal-at-point-mode-alist '(web-mode . "html,css,javascript"))))
diff --git a/layers/+tools/shell/packages.el b/layers/+tools/shell/packages.el
index 832ec34ed..22345efe9 100644
--- a/layers/+tools/shell/packages.el
+++ b/layers/+tools/shell/packages.el
@@ -117,12 +117,12 @@
 
       ;; Visual commands
       (require 'em-term)
-      (mapc (lambda (x) (push x eshell-visual-commands))
+      (mapc (lambda (x) (add-to-list 'eshell-visual-commands x))
             '("el" "elinks" "htop" "less" "ssh" "tmux" "top"))
 
       ;; automatically truncate buffer after output
       (when (boundp 'eshell-output-filter-functions)
-        (push 'eshell-truncate-buffer eshell-output-filter-functions)))))
+        (add-hook 'eshell-output-filter-functions #'eshell-truncate-buffer)))))
 
 (defun shell/init-eshell-prompt-extras ()
   (use-package eshell-prompt-extras